Rotary impact type screw driver



Get, 11, 1949. E. TURGEON 2?4847@5 ROTARY IMPACT TYPE SCREW DRIVER FiledApril 12, 1946 Patented Oct. 11, 1949 UNITED STATES PATENT OFFICE ROTARYIMPACT TYPE SCREW DRIVER Application April 12, 1946, Serial No. 661,618

This invention relates to a screw driver or similar tool of thecharacter described in my previous Patent 1,743,505, January 14, 1930,and the object of the present invention is to improve the constructionof such tools for reducing manufacturing cost and for greater utility inuse.

As fully explained in my previous patent, the general purpose of such atool is for the removal or loosening of screws and the like which areset too firmly for removal by an ordinary means,

the reverse action of driving in a screw tightly to its seat, and mytool is designed for equal efficiency in either right or left handturning.

Referring to the drawings which show the present embodiment of myinvention,

Fig. 1 is a side elevation of the complete tool, the shank thereof beingof the screw driver type and in position for a camming right hand turn;

Fig. 2 is a partial section through the handle or driver of the toolshowing the interior engagement when the shank is fully home in itssocket;

Fig. 3 is a side elevation of the complete tool at right angles to thatshown in Fig. 1;

Fig. 4 is a detached View of the tool shank;

Fig. 5 is an enlarged detail of the upper end of the shank to show theposition of the locking pin in register with the release ramp in theupper groove of the shank;

Fig. 6 is a similar View to Fig. 5 showing the shank at right angles tothat in Fig. 5 with the locking pin out of register with the releaseramp of the said shank.

Referring more particularly to the drawings, the tool comprises a driverI which serves as a handle member and may be knurled on the outside asshown. This driver, as shown in Fig. 2, is provided with an internalaxial socket 2 opening out of its lower end and adapted to receivetherein the upper end of the tool shank 3, which is fitted in the socket2 for a limited longitudinal movement and a rotatable movement relativeto said driver.

The lower end of the driver I has a tubular wall surrounding theentrance of the socket 2, said wall being formed with two similar andoppositely disposed V-shaped cam members 4 and 5. The lower end of eachcam member converges to a relatively sharp apex such as at 6 and I andintervening between the upper ends or base portions of said cam members4 and 5 are two wall notches such as 8 which are at diametricallystocket 2 1 Claim. (Cl. 145-50) 2 opposite sides of said driver and oneof which is shown clearly in Fig. 3. The side walls of said notches 8are parallel to the axis of the driver. The shank 3 is provided with across lug 9 projecting from each side thereof and which is adapted toride on the cam surfaces on cams 4 and 5 and also to be lockably engagedwithin the notches '8 when the shank 3 is pushed inwardly to its extremehome position within the socket 2. The upper or inner portion of theshank 3 is formed with a rounded head Ill adapted to seat on the bottomof socket 2 and below said head with two annular grooves, viz. an upperrelatively wide annular groove at II and a lower relatively narrowerannular groove at I2. Adapted to selectively engage in either of thesegrooves is a looking pin I3 which is radially mounted in the side wallof the driver I and normally pressed by a spring I4 so as to insertitself in one of said grooves II or I2. The inner engaging end I5 ofsaid locking pin I3 is relatively sharp cornered and the upper shoulderof the groove I I is likewise sharp cornered in large part to form alocking shoulder against the end of said locking pin. l3.

' However, at diametrically opposite points of the upper shoulder ofgroove II there are formed beveled portions or release ramps I6 and H,see Figs. 5 and 6. When the shank 3 is turned to bring either of saidrelease ramps It and Il into register with the locking pin I3, the shankmay be easily withdrawn from the socket 2 against the yielding force ofthe spring pressed pin I3. Conversely when the pin I3 is not in registerwith said ramps I6 and H, the shank 3 is securely locked within thedriver I and while it may have a limited longitudinal movement therein,this movement will not be sufficient to allow the cross pin Q to rideover the apex 6 or I of the cams 4 or 5.

These release ramps I6 and H are located on the upper shoulder of grooveII to register with the locking pin l3 for easy release of the shank.When shank 3 is turned for registration of pin I3 with ramp IE or H theshank 3 may be withdrawn from the driver I but not otherwise. Thedividing wall I8 between the wide groove II and the narrow groove I2, asshown in Fig. 5, is formed with rounded corners so that the locking pinI3 may easily ride over the same in either direction in moving intoeither of said grooves II or I2.

In accordance with the above construction, it will be readily understoodthat when it is desired to use the tool as an ordinary screw driver theshank 3 is pushed all the way home into its so as to lock the lug 9.into the wall an ordinary screw 'driverror the like.

notches 8. The locking pin l3 at that time will be engaged in the narrowgroove I2 at the upper end of the shank and will hold the same firmly inposition so that the shank will turn with the handle'in either directionfor use "in the usual manner of a screw driver or similar tool. When itis desired to use the tool for loosening a stubborn screw which may havebeen frozen or rusted in position, the shank is pulled outfislightlyf inits socket to bring the locking pin [3 intuengagement with the uppergroove I I. The screw driver shank is then turned until the outeren'dofthe cams- 4 and 5 engage with the crossslug 9. Thereupon a sharp blowfrom a hammerz'against the :topLof the driver while holding it by handfrom" turning, will cause the shank to turn under great force throughthe coacting leverage of .the .cams4 and 5 on the lug 9. As fullydescribed in my previous patent, various other types of -shanks 3 may beused in my toolifor working on nut heads, broken screws, etc.

The advantages of my .present too1-over that shown in my previous patentare in the improved arrangement for convertingthetool into-use as.Thei'provision of the locking notches 8 and the double holding groovesM and 12 make possible a much cheaper constructioniforthe lower end ofthe cams'd and 5tthanin'my previous tool. Various other advantages'willtbe 'apparent'from the detailed description heretofore given ofmy'present tool.

What I claim is:

A rotary tool of'the class-:described comprising in combination, adriver serving'asa handle and having a shank receiving socketiand:entrance thereto in one end of said tdriverga shank: removably fitted:therein for '.'-longitudinal and :rotative movement with respectttosaid 'driver; the wall of said socket adjacent said socket entrancebeing formed into oppositely disposed depending V- shaped cams andnotchesiformedin-said'wall at Zthejuncture of the'adjacent'opposedicam'sur- 'faces of said cams, the sides 'ofeach'notch being parallel to theaxis 'of 'saidutool; the shankhaving *driver and shank together foraccommon rotative movement in either direction, means for detachablyholding said shank in the socket of said driver "and comprising a pairof longitudinally spaced "annular grooveson the inner end of said shank,

the wall separating said grooves having a rounded "surface, a lockingpin slidably mounted in said driver and'adapted to be selectivelyengaged in one .of. said ggrooves, the outermost groove with respect tosaid. socket being spaced from said "innerendofthe sshank a distanceequal to the lspacingbetween said locking pin and the bottom -of.thesocket said outermost groove being of substantially the same width asthe Width of the shank i-engaging end of said locking pin, the innermostgroove with respect to said socket being of a width substantially. equalto thelongitudinal travel of the shank lug on .thelsurfaceslof lsaidV-sha.pedcams, the engagementof the pin =with said outermostgrooveservingto holdthe shank lug in the aforesaid wall. notches,andtheengagement of said pin with saidinnermostgroove servingto limitthe longitudinal .movement -.of said shank when theshank lug. is inengagement .with said V-shaped .cams, the innermost shoulder .of saidinnermost groove beingformedwithabeveled ramp for the release of -said.-lo.cking pin, vand means to urge .said .pin inwardly against theshank.

.EDMOND TURGEON.

REFERENCES CITED The .Jfollowing references are "of record :in :athe

file of this patent:

